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PubMed1994

[Evaluation of the scanner and radiography in rheumatic pelvispondylitis].

We studied 20 normal subjects and 20 suffering from sacro-iliitis. The performance of the two techniques were compared in studying reports ROC curve from several readers. We assessed the performance of each technique and each sign: CT scan appears as a better technique than plain films. Some signs present a poor interest: osteophytes seen on CT or plain films, subchondral cysts seen on CT. In other respects, articular cartilage erosions, subchondral sclerosis are main signs as much on CT as on plain films. In conclusion, CT scan allowed an accurate analysis of sacro-iliitis. It has a better diagnostic value than plain films and, in case of doubt, should be performed to increase diagnosis sensibility and specificity.

Adult↗
PubMed1993

[Infantile autism among children in the county of Nordland. Prevalence and etiology].

Few epidemiological studies of infantile autism have been conducted in Norway. A prevalence of four per 10,000 children was found in Nord-Trøndelag. Studies from Sweden, England and Japan show prevalence figures of 2-13 per 10,000. Causal factors of autism are complicated, but many studies in recent years indicate that both genetic and neurological factors are important. The aim of this study was to establish the prevalence of infantile autism in Nordland county and look for causal factors and disabilities among the children. Together with the Autism-Team we found 28 persons, born between 1975 and 1991, who lived in the county in 1992. This gives a prevalence of 5.5 per 10,000. 21 were boys, seven girls, 26 were mentally retarded, 13 had no verbal speech. Nine had epilepsy. 13 children were diagnosed before the age of four. Different diseases and impairments associated with autism were discovered in 19 children. In the case of eight children we found associated disease. When a diagnosis of infantile autism is made, the child should undergo a thorough medical and neurological examination. This should include CT brain scan, EEG, chromosome analysis, and screening for metabolic diseases and intrauterine virus infections. Sometimes examinations of liquor and auditory brain-stem responses are indicated.

Adolescent↗
PubMed1993

[A case of pure trigeminal motor neuropathy].

A 38-year-old man suffering from pure trigeminal motor neuropathy was admitted with a complaint of occipitalgia. Neurological examination showed severe wasting of the left masseter muscle on chewing. The jaw deviated to the left when he opened his mouth. Cerebrospinal fluid analysis was normal. The CT scan demonstrated a low density area in the left masseter, temporalis, lateral and medial pterygoid muscles. On MRI, the lesion of the left masseter, temporalis, lateral and medial pterygoid muscles showed high intensity of T1 and T2 weighted images. The cervical MRI revealed the non-communicating syringomyelia. Blink reflex, auditory brainstem response and trigeminal sensory evoked potentials were normal. EMG findings from the left masseter showed a neurogenic pattern. Muscle biopsy of the left temporal muscle demonstrated only fibroadipose tissue. Therefore, the present case was diagnosed as pure trigeminal motor neuropathy. It was suggested that multiple sclerosis might play an important role in the pathogenesis of this illness.

Adult↗
PubMedDate not supplied

[Modern diagnostic and therapeutic methods in bronchiolo-alveolar carcinoma].

In this article is described problems of bronchioloalveolar carcinoma, with respect to increased incidence of adenocarcinoma and bronchioloalveolar carcinoma. It was observed that bronchioloalveolar carcinoma occurs more frequently in younger persons and in women. Etiology of bronchioloalveolar carcinoma is still unknown. There is not an obvious connection with smoking but connection with previous damage of lung parenchyma. Bronchioloalveolar carcinoma can be defined as neoplasm which is not of central origin , but is peripherally located; therefore the term "bronchiolo-" but not "broncho-alveolar" carcinoma. It grows along alveolar septa and lung parenchyma remains intact. There is three pathohistological subtypes of bronchioloalveolar carcinoma: mucinous, non-mucinous and sclerotic form and three radiological patterns: solitar, pneumonia-like and diffuse. Clinical features depend of the stage and patient are most frequently asymptomatic. They later present with chest pain, dyspnea, cough, hemoptysis and weight loss. Complications include bronchorrhoea and intrapulmonal shunts. These findings, together with laboratory analysis, radiological tests (including CT scans) and cytological or hystological proof of malignancy, make definite diagnosis. Therapy depends on the stage of disease and is identical with that of other subtypes of non-small-cell lung cancer.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed2005

Accuracy of single-detector spiral CT in the diagnosis of pulmonary embolism: a prospective multicenter cohort study of consecutive patients with abnormal perfusion scintigraphy.

BACKGROUND: Spiral computed tomography (CT) has emerged as a potentially conclusive diagnostic test to exclude pulmonary embolism (PE) in patients with non-high probability scintigraphy and is already widely used-sometimes as the sole primary diagnostic test in the diagnosis of suspected PE. Its true sensitivity and specificity has, however, not been evaluated previously in a large cohort of consecutive patients. METHODS: In a multicenter prospective study 627 consecutive patients with clinically suspected PE were studied. Patients with normal perfusion scintigraphy were excluded from further analysis. Single-detector spiral CT scanning and ventilation scintigraphy were then performed in all patients to diagnose PE, while pulmonary angiography was performed as the gold standard. The only exceptions were those patients who had both a high-probability VQ scan and a CT scan positive for PE: these patients were considered to have PE and did not undergo additional pulmonary angiography. All imaging tests were read by independent expert panels. RESULTS: Five hundred and seventeen patients were available for complete analysis. The prevalence of PE was 32%. Spiral CT correctly identified 88 of 128 patients with PE, and 92 of 109 patients without PE, for a sensitivity and specificity of 69%[95% confidence interval (CI) 63-75] and 84% (95% CI 80-89), respectively. The sensitivity of spiral CT was 86% (95% CI 80-92) for segmental or larger PE and 21% (95% CI 14-29) in the group of patients with subsegmental PE. CONCLUSION: The overall sensitivity of spiral CT for PE is too low to endorse its use as the sole test to exclude PE. This holds true even if one limits the discussion to patients with larger PE in segmental or larger pulmonary artery branches. We conclude that, in patients with clinically suspected PE and an abnormal perfusion scintigraphy, single-slice detector spiral CT is not sensitive enough to be used as the sole test to exclude PE.

Adult↗
PubMed2005

[Study of the morphologic variations of the scaphocephaly. Deduction for their systematisation].

PURPOSE: The scaphocephaly is the most frequent craniosynostosis secondary to a premature synostosis of the sagittal suture. Despite this univocal pathogeny there are a great heterogeneity in the skull deformation and their systematisation stay imprecise. The aim of this study was to analyse the different morphology of the scaphocephaly by 3D CT-scan to clarify the different shapes. MATERIAL AND METHODS: This retrospective study was done from the morphometric analysis of forty-two 3D CT-scan (10 girls and 32 boys). The scaphocephaly was classified in two groups according to the systematisation of Stricker and Montaut: the sphenocephaly (large forehead) and the leptocephaly (narrow forehead). The variation of the calvaria shape was analysed and different index were calculated. RESULTS: There were 30 sphenocephaly and 12 leptocephaly. Excepted for the forehead deformation there was a morphometric difference of the occipital pole that was backward rotated in the leptocephaly. In the two groups there were retro-coronal constriction (40.5%) or pre-lambdoid constriction (9.5%) independently of the sagittal synostosis degree. CONCLUSIONS: The morphometric analysis shows that the deformation of the skull secondary to the premature synostosis of the sagittal suture can be different. The adaptative defect of the metopic suture can be to explain this difference. This deformation can be harmonious, or with a retro-coronal constriction resulting in a bitemporal narrowing, or with a pre-lambdoid constriction resulting in an occipital chignon. These results conduce to qualify the surgical correction to adapt at the different shapes.

Child, Preschool↗
PubMed1997

Assessment of intraaxial and extraaxial brain lesions with digitized computed tomographic images versus film: ROC analysis.

RATIONALE AND OBJECTIVES: The authors evaluated the diagnostic accuracy of viewing computed tomographic (CT) scans as film versus soft-copy images at a workstation. METHODS: Receiver operating characteristic analysis of the interpretation of 202 CT scans (103 were normal, 99 were abnormal) by five neuroradiologists was performed. Abnormal images contained high- or low-attenuation intraaxial lesions or extraaxial fluid (subdural, subarachnoid, or epidural hemorrhage). Hard copies were read on a standard light box, and digital images were examined at a 1,024 x 1,250 workstation. Lesion location and type and confidence ratings were recorded on a worksheet. RESULTS: There were no statistically significant differences in diagnostic accuracy between the two display modes. Reader performance was slightly better with the workstation in the assessment of low-attenuation lesions. CONCLUSION: Diagnostic accuracy is similar for CT scans displayed at a workstation and those displayed as hard copy in the assessment of subtle intra- and extraaxial brain lesions.

Brain↗
PubMedDate not supplied

Ablation of liver metastasis: is preoperative imaging sufficiently accurate?

The recent introduction of cryotherapy and radiofrequency ablation of liver metastasis has expanded the indications for treatment. As technology has advanced, a percutaneous approach has been developed. Percutaneous treatment, however, requires accurate preoperative imaging. From 1993 to 1999, 179 patients underwent operative exploration for treatment of suspected hepatic metastases from colorectal carcinoma. One hundred seventy-seven patients were staged by preoperative CT, two patients were staged by MRI, and complete data were available in 176. Hepatic tumor count by preoperative imaging was compared to intraoperative tumor count obtained by inspection, palpation, ultrasonographic examination using a 3.5/7.5 MHz T probe, and careful gross sectioning of the resected specimen. Post hoc analysis was performed on 35 CT scans by two radiologists who specialize in abdominal CT. These radiologists were blinded to the intraoperative findings. Their interpretations were compared to the intraoperative counts and to each other. Thirty-four (19%) of 179 patients were deemed untreatable at operation because of unsuspected overwhelming liver involvement in 11 (6%) or extrahepatic metastases in 23 (13%). For the group, CT was accurate in 80 patients (45%), showed more lesions than were found in 16 (9%), and showed fewer metastases than were found in 80 (45%). When the preoperative scan predicted a solitary metastasis, it was correct in 45 (65%) of 69 patients and underestimated disease in 24 (35%). In the post hoc analysis, the mean numbers of lesions reported by the two radiologists did not differ from the mean number of tumors found; however, the radiologists' counts agreed on 16 (59%) and disagreed on 11 (41%) of the scans. The accuracy of CT decreased with increasing numbers of lesions. Regardless of the type of preoperative imaging, intraoperative findings altered the course of the operation in 96 (55%) of 176 patients. Preoperative imaging is not sufficiently accurate to permit adequate percutaneous treatment of hepatic metastases from colorectal carcinoma.

Bias↗
PubMed2005

[Individualized dose requirement for spiral-CT analysis of the abdomen].

PURPOSE: To search for individualized scan protocols that provide adequate diagnostic information with minimal radiation exposure for abdominal CT in adults. MATERIAL AND METHODS: Beginning with standard settings (120 kVp, 200 mA, 0.75 s, CTDI (w = 11.7 mGy)), which are in the lowest quartile of the actual German radiation dose survey, 119 adults were examined using a single-row detector helical CT with 8 mm collimation and a pitch of 1.5. The individualized scan protocol was defined by repeating the reference scan up to 3 times with different radiation doses following a predefined iteration scheme. The image qualities with standard dose and with individualized dose were assessed independently by 3 radiologists blinded to the exposure parameters. The individualized dose was correlated with the diameter of the patients. RESULTS: The patient diameters varied from 16 to 35 cm and correlated with individualized radiation doses CTDI (w) from 6.4 to 17.6 mGy. We found an exponential correlation (y = 52.3 x e (0.05 x); r(2) = 0.48; p < 0.001) between required tube current (mA) and a. p. diameter (cm) in the epigastric region in adults. CONCLUSION: Maintaining constant exposure parameters results in unnecessary radiation exposure in patients with a diameter of less than 27 cm measured in anterior-posterior direction in the epigastric area. The radiation exposure in adult abdominal CT can be reduced up to 45 % by individualized selection of the tube current without adversely affecting diagnostic performance.

Adult↗
PubMed1982

[Advantages of thoracic CT scanning in the treatment of mediastinal lymphomas].

In order to study the possible advantages of thoracic CT scanning in the management of mediastinal lymphomas, a retrospective analysis of 16 patients was carried out. In this group, 21 thoracic CT scans were performed. For 10 patients (and 11 CT scans) we found a discrepancy between the results of "classical" radiology and those of CT scan, the latter giving more information about the precise status of the mediastinum. In 10 cases, we had to modify our treatment, either by adding chemotherapy or changing the radiation field size.

Adolescent↗
PubMed1977

Periventricular hypodensity in hydrocephalus: a clinico-radiological and mathematial analysis using computed tomography.

The computed tomography (CT) scans carried out in hydrocephalic patients before and after surgical treatment [cerebrospinal fluid (CSF) shunting] were assessed by analysis of the densities. The numerical data were compared to the pictorial record on the display console. The periventricular hypodensity was correlated to the clinical parameters and to the time lapse after surgical treatment. The subependymal hypodensity shows good direct correlation to the transit of CSF from the ventricles to the white matter, and to the clinical status of the patients. The mathematical analysis supplies objective data and comparable indices. It constitutes the starting point for an automatic evaluation of the CT images of the process of transependymal CSF resorption in non-treated and treated hydrocephalus.

Absorptiometry, Photon↗
PubMed2005

Changing opioid use for right lower quadrant abdominal pain in the emergency department.

OBJECTIVES: To compare the use of opioid analgesia in the treatment of emergency department patients with acute right lower quadrant (RLQ) abdominal pain between 1998 and 2003 and to explore the relationship between opioid use and abdominal computed tomography (CT) scanning. METHODS: This was a retrospective cohort study of patients presenting in 1998 and 2003 to an urban emergency department with a triage complaint of RLQ pain. The authors abstracted use and timing of abdominal CT scanning and opioid analgesia. Other predictor variables were patient demographics. Risk ratio for receiving opioids with CT scan versus without CT scan, stratifying by year, were calculated. Proportional-hazards analysis was used to control for time in the emergency department. RESULTS: Of the 187 patients seen in 1998, 38 (20%) underwent CT scanning and 43 (23%) received opioids. Of the 137 patients seen in 2003, 77 (56%) underwent CT scanning and 72 (53%) received opioids. In 1998, the risk ratio for receiving opioids in patients who underwent CT scanning (vs. without) was 3.7 (95% confidence interval [CI] = 2.3 to 6.1); in 2003, it was 1.5 (95% CI = 1.0 to 2.1). Opioids were overwhelmingly given before CT scanning in those patients who received both (81% in 1998 and 98% in 2003). The mean time to administration of the first opioid dose in 1998 was 155 minutes and in 2003 was 94 minutes. The proportional-hazards analysis confirmed a strong association between CT scanning and opioid administration in 1998 (relative hazard, 2.7; 95% CI = 1.5 to 5.1) and substantial attenuation of the association in 2003 (relative hazard, 1.3; 95% CI = 0.8 to 2.1). The hospitalization rate was not significantly different in 2003 (33%) versus 1998 (27%) (p = 0.28). The risk ratio of receiving opioids in admitted patients was 2.8 (95% CI = 1.7 to 4.6) in 1998 and 2.0 (95% CI = 1.5 to 2.7) in 2003. CONCLUSIONS: Opioid administration to patients with RLQ pain has dramatically increased between 1998 and 2003. During these five years, the number of patients receiving opioids more than doubled and the time to first administration of opioids decreased by one hour. The authors show that this cannot be attributed to an increased use of CT scanning.

Abdominal Pain↗
PubMed1991

Paranasal sinus bony anatomic variations and mucosal abnormalities: CT analysis for endoscopic sinus surgery.

Coronal plane computerized tomographic (CT) scanning has dramatically improved the imaging of paranasal sinus anatomy as compared to sinus radiographs. Increasingly, subtle bony anatomic variations and mucosal abnormalities of this region are being detected. Data regarding the "background" prevalence of these findings are needed to determine their clinical relevance. A detailed analysis of coronal plane CT scans of the paranasal sinuses obtained in 202 consecutively imaged patients was conducted. Special attention was directed toward identifying bony anatomic variations and mucosal abnormalities. Anatomic variations studied included pneumatization of the middle turbinate, paradoxical curvature of the middle turbinate, Haller's cells, and pneumatization of the uncinate process. Such bony anatomic variations were detected in 131 (64.9%) of 202 patients and were found with a similar frequency in patients scanned for sinus complaints and in those scanned for nonsinus reasons. Mucosal abnormalities were detected in 168 (83.2%) of 202 patients. For those patients scanned during the evaluation of sinus-like complaints, mucosal abnormalities were noted in 153 (92.2%) of 166 cases, and were predominantly detected in the anterior ethmoid region. For patients scanned during nonsinus evaluations, mucosal abnormalities were detected in 15 (41.7%) of 36 cases, without predilection for the anterior ethmoid region. Discussion regarding the prevalence and clinical significance of paranasal sinus bony anatomic variations and mucosal abnormalities is included as a guide to assist the otolaryngologist and/or radiologist in the evaluation of coronal sinus CT scans.

Adult↗
PubMed1994

[The value of CT for the diagnosis of rectal cancer recurrence. A ROC study and a retrospective analysis].

To assess the ability of CT to detect recurrent tumor growth after colorectal surgery for rectal carcinoma independently of clinical bias and patient selection, a receiver operator characteristic (ROC) analysis was performed. A set of 100 CT scans, 50 scans of 35 patients with proven recurrent disease, and 50 normal postoperatives of 37 patients were read by four observers without knowledge of the present clinical status. The four ROC curves had an area under the curve (AUC) ranging from 0.69 to 0.78 (SD from 0.046 to 0.053). The slightly raised AUC indicates the poor diagnostic power of CT in discriminating between postoperative changes and recurrence. In a retrospective analysis of the CT scans of the 72 patients CT had an overall accuracy of 83%. CT was unable to detect small anastomotic recurrence. The morphological characteristics of recurrence were not specific, but an irregular globular mass with or without inhomogeneity or asymmetry strongly suggests recurrent tumor and stresses the need for further evaluation, e.g., CT-guided biopsy.

Female↗
PubMedDate not supplied

Paranasal sinus development in chronic sinusitis, cystic fibrosis, and normal comparison population: a computerized tomography correlation study.

Chronic sinus disease in patients with and without cystic fibrosis may have an impact on the pattern of paranasal sinus pneumatization. Arrest of pneumatization has been reported in both of these conditions. To assess the development of the paranasal sinuses in relationship to chronic sinusitis and cystic fibrosis (CF), a retrospective review of coronal CT scans of the age-matched patients with no previous sinus disease, patients with chronic sinusitis, and cystic fibrosis patients was conducted. The patients' ages ranged from 4 to 17 years. The maxillary sinus volume, anteroposterior diameter, and greatest transverse diameter and height were determined using image analysis software after the coronal CT scans were scanned into Macintosh computer. The size of the maxillary sinus increased with advancing age in the control and chronic sinusitis group, but not in the patients with cystic fibrosis. The patients with cystic fibrosis had a statistically significant smaller maxillary sinus size. Approximately 50% of the patients with chronic sinusitis had anatomic anomalies, the most common being paradoxical middle turbinates. The CT scans of CF patients were characterized by uncinate process demineralization and medial displacement of the lateral nasal wall in the middle meatus, and decreased maxillary sinus pneumatization.

Adolescent↗
PubMed1996

Use of a biocompatible fiducial marker in evaluating the accuracy of computed tomography image registration.

RATIONALE AND OBJECTIVES: Accurate registration of computed tomography (CT) images to the patient is crucial for computer-assisted surgery. Markers used in roentgen stereo-grammetric analysis (RSA) can be located in a CT scan using a novel approach and also can be located physically. Roentgen stereo-grammetric analysis data act as "ground truth" for the three-dimensional marker locations. METHODS: Two foam-bone phantoms were marked. The markers were scanned seven times with RSA, three times with axial CT, and contacted four times with a coordinate measuring arm. Root-mean-square (RMS) errors were derived for the registrations. RESULTS: Computed tomography and RSA data register to 0.15 mm RMS error. Computed tomography and arm data register to 0.25 mm. The markers are biocompatible, and the coordinate measuring arm is usable in an operating room. CONCLUSIONS: Typical in vitro registration errors are approximately 2 mm. The authors have developed a marker that provides superior registration, and a procedure that can be used for in vivo studies.

Biocompatible Materials↗
PubMed2002

Determination of orthotropic bone elastic constants using FEA and modal analysis.

Finite element models have been widely employed in an effort to quantify the stress and strain distribution around implanted prostheses and to explore the influence of these distributions on their long-term stability. In order to provide meaningful predictions, such models must contain an appropriate reflection of mechanical properties. Detailed geometrical and density information is now readily available from CT scanning. However, despite the use of phantoms, a method of determining mechanical properties (or elastic constants) from bone density has yet to be made available in a usable form. In this study, a cadaveric bone was CT scanned and its natural frequencies were measured using modal analysis. Using the geometry obtained from the CT scan data, a finite element mesh was created with the distribution of density established by matching the mass of the FE bone model with the mass of the cadaveric bone. The maximum values of the orthotropic elastic constants were then established by matching the predictions from FE modal analyses to the experimental natural frequencies, giving a maximum error of 7.8% over 4 modes of vibration. Finally, the elastic constants of the bone derived from the analyses were compared with those measured using ultrasound techniques. This produced a difference of <1% for both the maximum density and axial Young's Modulus. This study has thereby produced an orthotropic finite element model of a human femur. More importantly, however, is the implication that it is possible to create a valid FE model by simply comparing the FE results with the measured resonant frequency of the CT scanned bone.

Anisotropy↗
PubMed1993

Incomplete interlobar fissures: bronchovascular analysis with CT.

Thin-section computed tomographic scans of both lungs in 154 patients, including seven cadavers, with lung cancer (n = 37), diffuse (n = 32) or inflammatory (n = 30) lung disease, other proved or suspected disease (n = 23), or healthy lungs (n = 32) were analyzed to determine the frequency of incomplete interlobar fissure (IIF). An IIF was defined as a discontinuous linear shadow that remained in contact with the chest wall. An IIF was found in 128 of 154 right lungs (83.1%) and 77 of 154 left lungs (50.0%). Some bronchovascular structures crossed or passed through two contiguous lobes in the fused area. The most common bronchovascular structure associated with an IIF was a pulmonary vein; this association was found in 87 right lungs (56.5%) and 20 left lungs (13.0%). An IIF was traversed by a pulmonary artery in only seven right lungs and 13 left lungs or by a bronchus in only three lungs. It is concluded that recognition of an IIF might improve understanding of the spread of pulmonary disease.

Bronchi↗